Arc lamp and circuit therefor



y 1950 D. REICI- 'HNSTEIN 2,508,192

ARC LAMP AND CIRCUIT THEREFOR Filed Feb. 26, 1946 2 Sheets-Sheet 1 WWW/Mm May 16, 1950 Filed Feb. 26, 1946 D. REICHINSTEIN ARC LAMP AND CIRCUIT THEREFOR 2 Sheets-Sheet 2 58 Fig. 4

I II

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M/l EN TOR TTORNEVS Patented May 16, 1950 Application February 26, 1946, Serial Nor 650,354 :In Switzerland March. 7,1945

Claims. (CL' 315102) 1 It is 115L131 in -.enclosed;.-gas-discharge lamps, *Whosel-ight derives exclusively from the incandescent electrodes,-to-use spherical or hemispherical tungsten: electrodes. 2 Electrodes of this type present thesdraw back that their reverse sides are less incandescent than those that face each .'other, and for this reason do not emit sufficient light.

Extensive experiments carried out by me have :led to the .=result that it is advantageous to .employ hollowahemisphericalelectrodes, and in general electrodes with concave-convex faces. .Thehollowing of .-the:.electrodes renders them -..thinner, andv consequently'the outer faces become just asiincandescentas the inner ones.

Further experimentsled-to the result that with the. help of electrodes With concave convex' faces the irradiation in a desireddirection can i be ,greatly \amplified, other things being equal, if the electrodes are so fitted that their inner sides do not exactly face each other-in which case .therays fromthe inner side of oneelectrode are =caught-by the innersidc-of the other, and vice wversa.but..by fitting the electrodes so that they rare-somewhat rotated round theirsaxis. In this .case the inner sides of both electrodes direct .Ltheir raysat least partially-outwards in a desired direction.

llhelaccompanyingdrawing illustrates by way of example 1 a. satisfactory embodiment of -th invention. .In.said,drawing:

fliig -lshows a top-view. of the main electrodes of the lamp;

Fig. 2 shows schematically-a lamp constructed .inaccordancewith the invention;

Fig. 3 slampaancl iiFigsmi-and 5 show-diagrammatically the vari- .=.011s. steps :inthe operation of the switches shown nin'rFigm3. V

Fig. lshows-ltheaarcuate electrodes Sand! in ..rotatedposition. :.It. is evident that, asa result toftthe rotationnof the electrodes, distance [3 is .smaIIer-than distance-i2. The arrow in the center .of the figure indicates the, direction of the desired irradiation. Nevertheless, in" this case too, .the .most valuable portion of the light remitted bythe two facing sides of the electrodes his-lost.

As regards the electrodes, the present invention consistsein providing the. parts of the two lelectrodesthat face each other with holes. These iholes.are.not,.however, at thesame level; i. e. do not lieopposite each other. For instance, incandescent electrode't can emit rays through holes "1'0 and in electrode!, and the corresponding representseacircuit for .operating the I lin'candescent ,part -.of electrode]. can emit rays rauxiliary electrode .2].

, .through.,holes-..8. and}; in electrodefi.

.By surrounding .theelectrodes with "a pro- ,.jectingmirrorv inesuch. a .Waythat not .only the irradiationof the inner sides .of the electrodes through thenholes, but..;also that of their outer sides, .is directed inv the dine of projection, the irradiation canhe .ntilizedto -a .high. degree for purposes of projection.

Lamps fitted .witlna ,proj ecting.. mirror of this .type can be employed not only -for projection purposes, but also for illuminating,largerooms and even. streets.

The lamp 1 this. reproduced ,in. itsentirety in Fig. 2. Here l5. =is..the glass-bulb, whoseneck Hi .can in very poweriul lamps .be surroundedwith a, cooling. Water. jacket. in neck 16 .issuspended cylinder ll calledithe chimney. The .spacelbetween neck I6. and ,chimney I! is filled. with steel wool l8 for the purpose ..-of intercepting the .sublimed. particles .of .-.t.ungsten,..in. ,order to prevent the sidesof the bulb,. from becoming covered .with sootlthrough long. ,usage.

Close to mainelectrodes .19.,and ZEl-is fitted JIfheir conductors are welded-into crystal base .22.. and, terminate inc-4 .jfirmlylfixed pins. 2.3,for,.p1ugging into a four-pole .socket. (The. lamp can-Joe. filled withapure inert gas. oriwith-a mixtureof inert gases, oneof which is. nitrogen.

With respect. to. the circuit, thegpresent invention vis characterizedin that, thearclamp is fed fromwai lighting. main lor -electricaldistribution .network oianyvoltage over a simple 4 or 3step switch. and with the. insertion, ofna; small trans- -.former. The laststepof theswitchconnects the .lamp, directly .to. the main and .at the .same time excludes the transformer.

-.In Fig.3,5l representsthe lightingmain. 36, Miami138,.1Ziaare twoprimary windings of the .transformer. ..If .thevoltage-of .the .main. is ,220 volts these two .\ri.nclingsv are connected in series,

if it, isl2fl voltsltheysare connected in parallel.

..In-.ho'th casessecondary winding 4!], .42 gives .anEiMuFvof 420 volts, while the other. secondary winding i3, 4! connected. in serieswith the former gives 20. volts. .Thissecond winding is also -utilized for heatingthe wireof the auxiliary electrodeof thelamp. 44,. 49, @Eareimpedances;

"ii and."l.are the main electrodes of the lamp,

while 2! represents the Wire of the auxiliary electrodejZi), 30, 33, 34, 24,'26,. 28,.2'i, Z5 represent a l-step switch that can effect the following connections by! the actuation of, a single lever:

'Step.I.-Connects.29 with 33 and 3D With 34,

whereby main -51 is connected over terminals 3|, 32 to the primary winding of the transformer.

Step II.Connections 29, 33 and 3|], 34 are maintained, but at the same time 24 is connected with 26 and 28 with 21. Thereby main electrode 6 is connected with terminal 40 of the secondary winding over impedances 49 and 44, while terminal 4| of the secondary Winding is connected with auxiliary electrode 2| over 28, 21. By pressing the button of switch 35 the wire of auxiliary electrode 2| is connected with the 20-volt secondary winding of the transformer and becomes incandescent. This results in the formation of an auxiliary are between 2| and main electrode 3.

As soon as the main electrode is heated to a dull red the switch can be turned to step III.

Step III.-Connections 29, 33 and 30, 34 are maintained as is connection 24, 25, while 28 is now connected to 26. Thereby the other main electrode is connected with terminal 4| of the secondary winding of the transformer, while incandescent lamp 59 is inserted in the circuit of the auxiliary arc. The ohmic resistance of lamp must be much greater than the sum of 44 and 49 and is so determined that the arc passes on to the second main electrode. When the latter is sufiiciently heated by the arc, lamp 50 is extinguished. A vital part of the present invention consists in that the automatic extinction of lamp 50 affords an indication that the arc lamp can be switched directly over to the main step IV.

Step IV.-Connections 29, 33 and 30, 34 are broken, while 24 is connected with 29 and 25 with 39. This completely excludes the transformer and connects the lamp to the main.

It should be mentioned that step I can be eliminated, while on the other hand the lever switch can be replaced by a roller switch. Nevertheless the following description of the lever switch will go to prove that such a device possesses particular simplicity and handiness.

Small copper plates are fitted at different levels on the inside of two semi-circular sheaves made of insulating material and facing each other. A lever, also of insulating material, rotates round an axle placed beneath the plates. This lever is fitted with metal pins which, on turning the lever, engage in hollows in the plates here symbolized by small circles. In Fig. 4 can be seen triple plate 52 which is connected with single plate 54 situated on the third level of the insulating sheave by copper wire 53 fitted on the outside of the sheave. Single plate 62 must be fitted on the second level in step IV of the opposite semi-circular sheave Fig. 5, in the upper level of which is fitted triple plate 59. It is evident that, in order to achieve a practical and simple connection of single plate 62 with triple plate 63 on the first level, the latter must likewise be fitted on the same sheave Fig. 5 on which is fitted plate 59. The latter, and triple plate 58 on Fig. 4 as well, are not permanently connected to the main, but with the primary winding of the transformer, and are identical with contacts 33 and 34 in Fig. 3.

It should also be mentioned that double plate 55 on the third level of Fig. 4 is symbolized in Fig. 3 by contact 26, while 52 and 54 are identical with 29. Plate 56 of Fig. 4 is identical with 21 in Fig. 3; triple plate 60 on the third level of Fig. 5 corresponds to contacts 24 in Fig. 3; double plate 6! on the second level of Fig. 5 corresponds to con tacts 28 in Fig. 3, and 62 and 63 correspond to contacts 39 in Fig. 3.

As, however, single plate 62 is fitted on the second level, triple plate 63 must be fitted on the first level, in order that it may be easily con- 4 nected with the former by wire 64. It will be seen that in step IV only plates 54 and 51 on the sheave represented in Fig. 4 are connected with plates 59 and 62 on that represented in Fig. 5, while transformer connections 58, 59 are broken.

Summing up, this switch can be designated as a 4 or 3 step, 2-pole sliding lever switch.

With respect to the circuit, it is characterized first of all by the automatic extinction of lamp 50 as a signal for switching over to the main. Secondly this circuit is characterized by the compensating introduction in the 440-volt circuit of the secondary winding of the transformer of a current of such intensity as to give rise to a suitable voltage at the terminals of the arc lamp for the purpose of switching over to an appropriate lighting main by inserting adequate impedance 49. For this reason the circuit can be designated as a signal-compensation circuit.

I claim:

1. An arc lamp supplying a continuous spectrum and comprising a glass bulb provided with a neck and containing an inert gas, a wire auxiliary electrode, a manual switch connected with the latter, perforated main electrodes arranged at the same elevation and presenting convex surfaces to each other, the rear surfaces of the main electrodes being concave, said main electrodes being mounted in rotated relation with respect to each other and are so mutually disposed that, viewed in section along the central plane common to said two main electrodes, the one pair "of ends of the electrodes opposite one another have a greater distance from each other than the other ends, for the purpose of obtaining a larger uncovered radiating electrode surface, a compensated network for connecting the lamp to an electrical distribution network and including a main current circuit and an auxiliary arc circuit, a signal lamp in the auxiliary arc circuit, .an impedance common to the main current and auxiliary arc circuits, the distance of the wire of the auxiliary electrode from the main electrodes and said common impedance on the one hand, and such impedance and the impedance of the signal lamp on the other hand being so determined with respect to each other that upon simultaneous cutting in of the signal lamp and of the main current circuit, the signal lamp lights up and in a short time is automatically extinguished, whereby there is provided a signal for switching the now glowing main electrodes to the distribution network.

2. Are lamp according to claim 1 wherein the main electrodes have concave-convex surfaces and are turned about their axes.

3. Arc lamp according to claim 1 including a glass cylinder inside of the neck of the bulb, the space between the inner wall of the bulb neck and the outer wall of the glass cylinder being filled with steel wool for receiving the tungsten soot.

4. Are lamp according to claim 1 wherein the auxiliary electrode is operated by a small voltage portion which is in series with the main voltage operating the main electrodes, said auxiliary electrode being brought to incandescence by operation of the manual switch, the auxiliary arc thereby produced becoming automatically extinguished at a definite moment of the actuation of the switch arrangement.

5. An arc lamp supplying a continuous spectrum and comprising a glass bulb provided with a neck and containing an inert gas, perforated, main electrodes arranged at the same elevation and presenting convex surfaces to each other,

atoms 5 the rear surfaces of said main electrodes being concave, said main electrodes being mounted in rotated relation with respect to each other and being so mutually disposed that, viewed in section along the central plane common to the said electrodes, the one pair of ends of the electrodes opposite one another have a greater distance from each other than the other ends, for the purpose of obtaining a larger uncovered radiating electrode surface, a network connected with the lamp and including a multi-step switch, a transformer having asecondary coil comprising two part connected in series, an auxiliary electrode, a common impedance, a second impedance, and a manual switch, said parts being connected electrically with each other and with one of the main electrodes when the first-mentioned switch is in one of its positions, the next position of the switch closing two circuits simultaneously, one of the said circuits containing both main electrodes while the other contains the auxiliary electrode and also a 6 signal lamp, said lamp having an impedance which is so dimensioned with respect to the other impedances and also with the impedance of the path between the auxiliary electrode and the main electrode that an auxiliary arc exists until the main arc glows fully, whereupon the auxiliary arc is automatically extinguished, said first-mentioned switch in its next position making connection only between the main electrodes, an impedance and the electrical distribution network.

DAVID REICHINSTEIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,158,441 Carpenter Nov. 2, 1915 1,290,930 Devers Jan. 14, 1919 2,177,696 Ewest Oct. 31, 1939 

